Grenade launcher



Dec. 7, 1948A. J. c. GARAND GRENADE LAUNGHER Filed 'may 12, 1947 wuvwto/a jQ/M/mM/MM Patented Dec. 7, 1948 GRENADEA LAUNCHER --Johnv C. Garanti, Sprngfield,- Mass., assigner to the United- States of Americaasvrepresentedeby the vSecretarylof: War

Application May 12, 1,947, serial No. 747,579

' l (ernaar) (Granted under theact of AMarch, 1883as amended April 30, 1928; 370 O. G. 757) 6 Claims.

.l Theinventiondescribedzin,the'following speci.-

cation Aand claims'mayfbeumanufactured and used byior for the Government yfor governmental purposes without the-payment tome of any royalty thereon. .l

i, rllhis` invention relates; `tu aL-,device for facilitating the launching offg-renades from rearms and relatesmore particularly `to a grenade launcher for gas-operated semi-automatic, firearms ofthe type illustrated `in the Garand Patent No. 2,377,338. i

As is well known, a grenade launcher is customarily attached to the-muzzle of a rearm and a grenade may be discharged therefrom by ringa blank `cartridgein the firearm. In order to reduce the high pressure of thegases evolved in launching grenades, there is customarily provided a valve assembly which upon opening allows a sulicient Vamount offsuchgases to `escape into the atmosphere and therebyprevents actuation of the recoiling membersof the iirearm.

In manyzof the launchers 4known inthe art, Atheopening of the grenade launching valve .is simultaneously accomplished `by the act of mounting the -V launcher onthe firearm. When 1 the valve is thus opened, itis obvious vthat the rearm can not be `used for firing regular ball ammunition. Yet in actualwarfare itis often of vital importance to re ball cartridges immediately after a grenade is launched from the rearm.` `As a result, certain priorart launchers were provided with means whereby proper adjust- `ment of the launcher permitted the valve to close upon the firing of'ia regular roundthrough the firearm. However, such adjusting means require manual manipulation of the launcher, and consequently valuable time is thus lostin preparing the firearm forordinary use.

It is therefore anvobject of "this invention to provide automaticmeansfor adjusting a grenade launcher to a position wherein the lvalve associated therewith will be permitted to close prior to the firing of a round through the firearm.

Another difiiculty encountered in prior art grenade launchershasbeenthat of retaining the grenade on the launcherprior toits discharge therefrom. Although accomplished at present by the use of a split ring or coil spring engaged in an annular groove at thel 4front end of the launcher, it has been found that the consequent buildingV up `of gas pressures against the front end of the launcher invariably causes k such grenade-retaining means to jump out of "the annulargroove.A Accordinglmit `is. also.Y an o bj ectI of this invenv 2 Ation'toprovde an; improved means for retaining a` grenade ona launcherfwhereby thehighmessure gases existing. about the front end of the launcherfupon the dischargeof agrenade will not interfere with the continuedoperation ofthe aforesaid means.

.The speciiic` natureiof the inventionr as well `as other objects and; advantages vthereof will; clearly appear from a descriptionlpf afpreferredembodimentes; shownin thefaccpmpanying drawings in which:

Mlig.,` Lisl a side elevational View of v.thevgrenade launcher of lthis,invention mounted onv the muzzle end of, areas-operated firearm;

Eig.;2:,is, a-view -similarrtoi- Fig. 1 Ibut showing the frontend'A and 'the-rearend of the grenade launcher in section;

Fig. 3 is an ,enlargedy(tppviewv of ,the rear end of the grenade launcher;

nFH/i; is an enlarged fragmentary view partiallycin. section 'showingy the cooperation of, the grenade launchervalvewith the Vstud on the launcher ;u and l f=Fig.,.5e.=is an4 enlarged fragmentary sectional view-lof. thegrenade-retaining means shown in Fig.: 2. Referring l,to IFig.' 1,. the: grenade launcher of this inventionis shownmounted .to the barrel'li oft av v.firearm.which, .for purposes :of illustration, is of the `typeidescriloed infill. S. Patent No. 2,377,838. A gas cylinders is supportedbeneath barrel 5 by means of andntegral-rear ,band (not shown) and. alf-front bandf. Aagas cylinder `lock 9; `is ,threadably :mounted ,onto `the muzzle end oibarrelyto.- secure gas cylinder E in place. A gas port lla-providedin barrel communicates with a ,sirnilargas-port` Hinlgascylinder 6 and thereby,r provides passage .for fthe actuating gases intol` gas Vcy-linderl.

Normally, a'standardgas cylinder lock screw is ithrea'dably secured -in the front end of gas cylindert. In Athe present'invention, however, the lock screw is ,not used but' instead there is ,provided asuitjable gas 4cylinder valveK screw l2 which seri/jesbothas a coupling for gas `,cylinder 6 and lock Bandas ameansforenabling the escape of gas from barrel., 5, inthe manner hereinafter `described l The immersed, grenade. launcher adapted vt0 be readilymountedlwithoutthe use of tools .on `the, mu,z,2;le` ,endL of,V barrel5 and adapted tobe ,latchedrs will vhe `later;shown, te theronfen- .tional` bayonety.111s f 30 found. ,011.,-mlitarvv Atyre @marins `The. launcher essentially Aesinlprllses,a

heavy-walled cylindrical tube I3, a bracket I4, and a latch I5.

At the front end of tube I3, as shown particularly well in Fig. 5, there is provided a threaded reduced-.diameter portion I6 adapted to receive thereon a threaded nut member I'I. When assembled to tube I3. nut member I'I is concentric therewith and provides an extension of substan-v tially the same diameter. Nut member I'I is countersunk as shown at I9. Extending from the rear of threaded portion I6 there is provided a raised annular portion I3 defining a shoulder 2| arranged to limit the rearward movement of nut member Il. To the rear of portion I8, tube I3 extends in reduced diameter section as far :as a shoulder 50. rThus when nut member I1 is assembled onto threaded portion I6, an annular recess 29 is defined by the rear end or' nut member I1 and shoulder 59.

There is provided in recess 20 a resilient washer-like ring 22 which is split as shown at 23 in Fig. l. The outer periphery of ring 22 normally extends slightly above the outer periphery of tube I3 and is beveled at the front as shown at 24 to mate with countersink I9 of nut member I'I. Thus, there is here provided a means for retaining a conventional grenade 25 (shown in dotted lines) in position to be launched when a blank of arm 29 there is provided a longitudinally eX- tending slot 3|. A hole 33 extends forwardly along arm 29 from the front end of slot 3| and is adapted to receive therein a coil spring 34 and the pin-like end 35 of a plunger 36. Plunger 36 is provided withv a body portion 31 substantially rectangular in shape and is provided with a transversely disposed elongated hole 38.

Latch I5 is provided with a pair of arms 39 pivotally secured at the rear of bracket I4, as shown in Fig. 3, by means of a pin 40 which also passes through elongated hole 38 and thereby retains plunger 36 in place and also limits the 1ongitudinal movement thereof. Latch arms 39 are connected by a downwardly and rearwardly eX- tending finger portion 4I. The front end of each arm 39 is provided with a depending lug 42, the

'l outer face of which is indented to form a detent cartridge is discharged in the firearm. The act y of mounting grenade 25 onto tube I3 over the bevel portion 24 of ring 22, compresses such ring to resiliently engage the inner periphery .of grenade 25. Such construction thereby prevents accidental displacement of grenade 25 from the launcher. Ring 22 is also beveled at the rear as shown at 5I thereby eliminating a sharp corner which might tend to create undue friction against the interior periphery of grenade 25.

A plurality of spaced slots 26 are provided circumferentially about tube I3 so as to intersect groove 26. Slots 29 extend substantially parallel with the longitudinal axis of tube I3 and decrease in depth rearwardly as shown in Fig. 2. When a grenade is mounted on tube I3y the compression of ring 22 opens a passageway between countersink I9 and beveled surface 24 for the flow of the gases emitted from tube I3 upon the discharge of a blank cartridge in the firearm. As a result, the gases enter recess 20 and are dissipated into the atmosphere through slots 26. In the event the bore diameter of grenade 25 is a maximum, the gases will enter recess 29 and consequently slots 26 by the way of split 23 since ring 22 will not be appreciably compressed. The

width of split 23 is such that closing thereof will f take place before ring 22 will bottom on raised annular portion IB. Thus even in the event of a minimum bore diameter in grenade 25, a passageway for the flow of the gases is still assured. If the gases are not dissipated in the manner described above, gas pressures would be built up in the vicinity of ring 22 of sufficient strength to force ring 22 out of recess 20.

Tube I3 is also provided with a series of annular grooves 2l about the outer periphery thereof which serve both to reduce the weight of the launcher and to minimize the friction on grenade 25 as it leaves the launcher.

Bracket I4 may be integral with tube I3 as shown or may be a separate member suitably secured thereto. Bracket I 4 is an L-shaped member having its shorter arm 28 extending downwardly from tube I3 and its longer arm 29 extending rearwardly in a plane substantially parallel to the longitudinal axis of tube I3. At the rear end portion 43. When the grenade launcher is mounted to the firearm, latch I5 is pivoted so as to engage the rear of bayonet lug 30. Thereupon detents 43 prevent accidental displacement of latch I5 from its bayonet-lug-engaging position until pressure is applied downwardly upon finger portion 4I. When the launcher is to be removed from the firearm, latch I5 is pivoted so as to disengage from bayonet lug 30 during which movement detents 43 are resiliently forced apart by the sides of bracket arm 29.

Valve screw I2 is provided with a gas passage 44 and a, slidable valve member 45 therein arranged to reciprocate longitudinally so as to open or close passage 44. A spring 41 surrounds valve 45 and is seated between an enlarged rear end 48 thereof and a shoulder 49 in gas passage 44. A longitudinal stud 46 extends rearwardly from bracket arm 28 vand provides means for opening valve member 45. As valve member 45 is moved to open gas passage 44, spring 4l is compressed. When the vlauncher counter-recoils forwardly in a manner to be described, valve 45 closes under the urging of spring 4l thereby permitting the normal usage of ball ammunition in the firearm.

When the grenade launcher is mounted on the firearm as shown in Fig. l, there is a slight clearance between the end of stud 46 and valve member 45. However, when a grenade is launched, considerable gas pressure acts upon the front end of launcher tube I3 causing it to recoil rearwardly. As a result, stud 46 moves valve 45 rearwardly thereby allowingl some of the gases evolved upon the discharge of the blank cartridge to escape through gas passa-ge 44 in valve screw I2. The rearward recoil movement of the launcher is cushioned and stopped by spring 34 which has been compressed by plunger 35 upon Contact with the front of bayonet lug 30. When the recoil pressure has subsided, the launcher is automatically returned to the position shown in Fig. l, by the urging of spring 34. Detents 43 prevent any downward pivoting of latch I5 during the recoil movement of the launcher, thereby assuring positive latching in cooperation with bayonet lug 39 upon the return to its pre-launching position.

Thus there is here provided a positive means for automatically returning a grenade launcher to a pre-launching position. As a result, conventional ammunition can be fired in the weapon without any of the delay or loss in time encountered in previous launchers wherein manual adjustment of the launcher is required to change from grenade launching to the firing of ball ammunition.

l'. claim:

1. In a grenade launcher for a gas-operated firearm having a gas cylinder and resilient valve means included therein, the combination of, a tubular member adapted to slidably t over the muzzle end of the firearm, a bracket secured at the rear end of said tubular member in laterally offset and longitudinally extending `relation therewith, a stud on said bracket in alignment with and operab-le to open the valve means in the gas cylinder upon recoil of the launcher, latching means on saidV lbracket constructed and arranged to engage a projecting part of the Vfirearm, and a spring-pressed plunger at the rear end of said bracket adapted to contact the projecting part of the firearm Whenthe launcher is mounted thereon, all adapted and arranged whereby said spring-pressed plunger is effective to cushion the recoil of the launcher and return the same to a pre-launching position.

2. In a device for launching projectiles from a firearm, a tubular member slidably mounted on the muzzlevend of the rearrn and adapted to receive a projectile thereon, said tubular member having an annular recess formed adjacent the front end thereof anda plurality of spaced slots circumferentially intersecting said recess, and a resilient split ring disposed within said recess and arranged to releasably engage the projectile, all adapted and arranged whereby said slots provide a passage for the iiow of the gases resulting from the launching of the projectile. f

3. In a device for launching projectiles from a firearm, a tubular member slidably mounted on the muzzle end of the firearm and arranged to receive a projectile thereon, said tubular member l having a front end portion of reduced diameter extending rearwardly to terminate in a shoulder, said reduced-diameter portion being threaded at the forward end thereof, a nut member assembled to said threaded front end thereby dening an annular recess in cooperation with said shoulder,

said nut member having a countersunk portion at the rear end thereof, said tubular member having -a plurality of spaced slots circumferentially intersecting said recess, and a resilient split ring disposed within said recess and extend'- ing into said countersunk portion, said ring arranged to releasably retain the projectile on said tubular member.

4. In a device for launching projectiles from a gas operated firearm, a tubular member slidably mounted on the muzzle end of the'rearm, said tubular member having a front end portion of reduced diameter extending rearwardly to terminate in a shoulder, said reduced diameter portion being threaded at the forward end thereof, a nut` member assembled to said threaded .front end thereby defining an annular recess in co` operation with said shoulder, said tubular member having a plurality of spaced slots circumferentiallyintersecting said recess, said nut member having a countersunk portion at the rear end thereof, a resilient split ring disposed within said recess, and a lfront bevel surface on said ringv charge gases into said slots thereby reducing the pressure against the front face of said ring.

5. In a device for launching projectiles from military type firearms having a bayonet lug thereon, the combination of, a tubular member slidablymounted on the muzzle end of the firearm, means on said tubular member for releasably retaining a projectile thereon, a bracket having a rst arm secured to said tubular member and a second arm extending longitudinally and rearwardly thereof `at substantially right angles to said rst arm,.

said second arm having a longitudinal slot of suii'icient width to surround the front edge of the bayonet lug, and a forwardly extending recess communicating with said slot, a spring seated in said recess, a plunger having a stem portion extending into said recess against said spring and a, body portion extending along said slot, said body portion having a transverse elongated hole therethrough, and a pin extending transversely through said second arm and through said elongated hole for limiting the longitudinal movement of said plunger, all adapted and arranged whereby the recoil movement imparted to the device by the launching of the projectile from said tubular member is eiective to compress said spring thereby urging automatic return of the device to a pre-launching position upon the cessation of thc recoil movement. f

6. The structure of claim 5 wherein said pin pivotally mounts a, latch engageable with the rear of the bayonet lug, said latch comprising a yoke-shaped portion havinginwardly facing detents for cooperation with the sides of said second arm to prevent pivoting of said latch during the recoil movement of the device, and a downwardly and rearwardly extending finger portion for manually pivoting said latch.

JOHN C. GARAND.

REFERENCES l CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,390,738- Rutherford et al Dec. 11, 1945 2,416,287 Coates et al Feb. 25, 1947 2,432,539 Olsen Dec. 16, 1947 

